Discharge lamp and lamp unit with caulking member

Abstract

A discharge lamp includes a luminous bulb in which a luminous material is enclosed and a pair of electrodes are opposed to each other in the luminous bulb; and a pair of sealing portions for sealing a pair of metal foils electrically connected to the pair of electrodes, respectively. The pair of metal foils have a pair of external leads on the side opposite to the side electrically connected to the pair of electrodes, respectively. At least one of the pair of external leads is joined to a lead wire for external connection that is to be electrically connected to an external circuit by the plastic flow of a caulking member.

1. A discharge lamp comprising:
 a luminous bulb in which a luminous material is enclosed and a pair of electrodes are opposed to each other in the luminous bulb; and  
 a pair of sealing portions for sealing a pair of metal foils electrically connected to the pair of electrodes, respectively;  
 wherein the pair of metal foils have a pair of external leads on a side opposite to a side electrically connected to the pair of electrodes, respectively,  
 at least one of the pair of external leads is joined to a lead wire for external connection that is to be electrically connected to an external circuit by plastic flow of a caulking member,  
 the caulking member is composed of aluminum or copper.  
 
   
   
     2. The discharge lamp of  claim 1 , wherein the caulking member has a cylindrical shape. 
   
   
     3. The discharge lamp of  claim 1 , wherein each of the pair of external leads is formed of molybdenum, and the caulking member is formed of a softer material than the molybdenum constituting the external leads. 
   
   
     4. The discharge lamp of  claim 3 , wherein the caulking member is formed of a material having excellent oxidation resistance properties. 
   
   
     5. The discharge lamp of  claim 1 , wherein the caulking member is composed of aluminum. 
   
   
     6. A lamp unit comprising the discharge lamp of  claim 1 , and a reflecting mirror for reflecting light emitted from the discharge lamp.